Unseizing Echo PB500T

[matthew.reck]

So here's the scoop, my dad purchased an Echo PB500T about two years ago at Home Depot, because it was on sale. This was one of the first two stroke engines he's had in a long long time, and forgot to mix the oil into the gas. He didn't realize this at all for a long time, as we kept using it more and more the engine began to die more and more every day until finally it said good bye. He took it to Home Depot for warranty service, they sent it back said the piston was frozen and it was gone, because he didn't mix oil in the gas. So he put it on the shelf for the next two years and in the meantime bought a bigger Echo, drained the gas and we forgot about it. Recently this week I decided to take on a summer hobby of trying to repair this bad boy, after a day of pulling the entire blower all the way down to the cylinder, I began battling to remove the piston from the cylinder. After lots and lots of wd-40 and some gas, I loosened and freed the piston from the cylinder, and quite surprised to find that the piston wasn't in a bad condition at all. So I used a little sand paper and sanded the piston down a bit, and the cylinder was fine. I cleaned all the parts slowly including the carb, and took everything apart down to the last screw before it was all put back together. Then, slowly put it all back together, I was able to get the cylinder slid back over the piston, and all screwed back together and was able to crank the engine! I pieced everything together and used our correctly mixed gasoline, and made my attempts to start the blower back up. For two days I've been trying to get this Echo going and can't, I'm stumped. I've tested the spark its fine, the gas is fine we use it all the time, the carb is clean, and the piston is moving. If I have the choke on it will sort of start to kick then dies after a short second. Any suggestions or help?! Please this is kinda a big deal to me as it will be the first real project I've fixed for my dad! (If you need pic's I'll happily take some)

[Pappy]

After sitting that long, my bet would be on the carb. 2 cycle cabs are simple but also somewhat delicate. The 2 diaphragms will dry out and develop pin holes. My SRM-210 edger was losing power and rough idling.

I cleaned the carb but it didn't help. A $12 rebuild kit from a local dealer did the trick and it runs like new.

Also look close at the primer bulb. A small leak there will prevent the flow of gas to the carb.

Last thing to check. There are 2 lines from the tank to the carb. The smaller ID is the 'feed' line and the larger line is the return. There are small and large fittings on the carb. The larger line goes on the smaller fitting. If you reverse them, it will start but run only if the tank is full enough to keep the end of the return line submersed. (DAMHIKT)

Make sure to have the serial # to get parts. Many Echo models underwent changes during the life of the model #.

[parnelli]

"Also look close at the primer bulb. A small leak there will prevent the flow of gas to the carb."

Hey thanks Pappy! I think you just fixed my trimmer

[eezlock]

unseizing Echo pb500T

I read your post and the reply from Pappy as well, he is definitely on the right track here. You should also replace those old fuel lines and pick up filter.
They are most likely seen better days by now as long as they have been sitting.
You might want to try a complete soaking of the carb in Seafoam cleaner,
I use it on mine and this stuff is really good, keep it completely submerged
in the cleaner overnight and then used compressed air to blow it out the next day. If that doesn't do the trick, either rebuild the carb or replace it, that is all
that this machine should need. eezlock

[matthew.reck]

Thanks Pappy, eezlock, and parnelli, I have already cleaned out the carb and soaked it in some good diesel, originally before we put it on the shelf we drained all the gas and the lines and made sure the carb was dry, so if we ever needed the parts for the new blower they were salvageable. The fuel line and primer bulb were also replaced when I began the project, may have forgotten to mention that. Yesterday I was able to get the engine to go for about 5 seconds! I added a few drops of gas, and straight 2stroke oil into the spark plug hole, and she fired up, very smokey, then died. So I began doing research I always mixed my gas in a 50:1 ratio, but had found that companies are going eco and squeezing as little gas in there possible, so I've mixed a fresh 40:1 batch for this blower put that in there and fired it up again, it worked for 5 seconds again, stumped I took it apart again, and noticed a minor detail I over looked. The piston ring was broken into pieces. I took it off and the minute I started doing that it fell apart even worse, I'm guessing the heat destroyed that thing, so anyway I ordered a new ring and piston from echo for about $40, and will replace that entire assembly, I figured while I was at it and the price being pretty cheap I'd fix it all. Ill keep you all posted, the parts arrive in a week or so.

[JSUPreston]

Just this weekend I finally got my Troy-Bilt 2 stroke trimmer running again. I let some of that ethanol gas sit in it for a while, and then it wouldn't crank. So, for the past 3 or 4 years, I've just pushed it out of the way when getting stuff out of the shop.

Earlier this summer, I bought all new lines, primer bulb, filter, and gasket. Spent about $60 on it. The old lines fell apart in my hands. After getting it all back together, it would fire but not run. I decided it was the carb. Found a guy on eBay selling new ones real cheap. Took longer to take the old carb off than to put the new on and test it. Works like a champ!

Not sure about your model, but my carb was about $15 with shipping. A rebuild kit was actually more. Since yours has been sitting so long, a rebuild or new carb is in order.

[capncarl]

If you ran the 2 stroke without oil that long, long enough to seize the cylinder, it probably is not worth the trouble to try to restart. The oil is only for lubrication of the roller bearings and piston, nothing to do with burning in the gasoline. I would doubt that the roller bearings nor the crank journals fared much better than the rings. 2 stroke engines that have bad rings are hard or impossible to crank because the compressed gas/fuel excapes out the exhaust pipe during compression and also back into the crank case and messes up the vacuum to the carb.
capncarl

[leehljp]

This is probably not related to your problem as you more than likely have found the culprit. However, A friend had a weedeater that he could not start. It would fire and then no more. Pulled the plug, add a few drops of gas, replace the plug, it would fire maybe 2 to 3 times, very weakly.

I went over to his house, did the same thing once, then removed the muffler to hear the firing. It ran immediately. Then I stuck a screw driver down the muffler exhaust port and removed a dirt/mud dauber nest. Replaced the muffler and it ran fine.

[matthew.reck]

Hey guys thanks for all the advice! I have successfully managed to reserve cut my once dead echo! I can get it to run full throttle and works great! I do have one concern... It's pretty smoky... Any ideas why? Thanks again! I also replaced all the fuel lines again and the kit for the carb and replaced all the gaskets